They are produced on an older processing node than the AM5 lineup. So if AMD switched to only produce AM5 CPUs and Radeon 7000 graphics chips, the old factories

They are produced on an older processing node than the AM5 lineup. So if AMD switched to only produce AM5 CPUs and Radeon 7000 graphics chips, the old factories would lack something worthwhile to produce. Therefore AMD can negotiate much lower rates for using those older facilities, making it viable to continue production as long as the products sell. There aren't any truly new chips, it is just new binning and marketing of the old models.